A 3D liquid crystal display device is capable of displaying stereoscopic images by displaying left eye images and right eye images. There have been realized various methods for displaying the left eye images and the right eye images, and the methods fall into two broad categories: a space division type and a time division type. In the present specification, a time-division type 3D liquid crystal display device will be described.
The time-division type 3D liquid crystal display device alternately displays the left eye images and the right eye images, and there may be problems of cross-talk, in which the left eye image and the right eye image are mixed while one image is switched to another. The cross-talk means that when the left eye images and the right eye images are alternatively displayed, an image displayed one frame before appears as the afterimage until the liquid crystal has completely transited. In order to reduce the occurrence of the cross-talk, each of the received left eye images and right eye images is divided equal to or greater than 2 so as to increase the frame rate, and black images are inserted between the left eye divided images and the right eye divided images. However, when the black image corresponding to a complete one frame is inserted, the frame rate considerably degrades apparently. Thus, Patent Document 1 discloses a method of inserting the black image segments into parts of the displayed image.
Please refer to FIGS. 14(a) to 14(d). FIGS. 14(a) to 14(d) illustrate black insertion of time division type 3D image according to Patent Document 1. As shown in FIG. 14(a), when the liquid-crystal display device receives, in parallel, interlace signals having the frame rate of 60 Hz (left eye images L1even, L1odd, L2even, L2odd, . . . and right eye images R1even, R1odd, R2even, R2odd, . . . ), the speed of each of the left eye images and the right eye images is doubled to have the frame rate of 120 Hz. Then, R1even, L1even, R1odd, L1odd, . . . are alternately displayed (FIG. 14(b)).
FIG. 14(c) illustrates, as an example, the black insertion in the left eye images and the right eye images alternately displayed in a pixel region with four rows and four columns (4×4). Each of pixels P11 to P44 has three sub pixels with color filters (red (R), green (G), blue (B)). When the left eye image L1even is displayed, the pixels P11 to P14, P31 to P34 at odd-numbered lines are displayed in black, and when the left eye image L1odd is displayed, the pixels P21 to P24, P41 to P44 at even-numbered lines are displayed in black. Human eyes can perceive a left eye image L1 by combining the left eye image L1even where the pixels at the odd-numbered lines are displayed in black and the left eye image L1odd where the pixels at the even-numbered lines are displayed in black. Similarly to the case of the left eye image L1, for the case of the right eye image R1, by inserting black in the pixel at the odd-numbered lines and the even-numbered lines of the right eye images R1 even and R1 odd and by combining both images, the human eyes can perceive the right eye image R1.